Mechanism For The Structure Features And Digestion Properties Of Starches In Intact Legume Cells Influenced By Cooking And Heat-moisture Process

Pulse is the fruit or seed of the family Fabaceae(or Leguminosae),which have 16,000–19,000 species in approximately 750 genera,including pinto bean,azuki bean,mung bean,broad bean,pea,cow pea,kidney bean,garbanzo bean etc.Evidence from a number of epidemiological studies strongly support the concept that whole pulses have functional properties that protect against metabolic disorders such as Type II diabetes and obesity.Pulses are known to have relatively thick and strong cell wall structures that could resist the cooking process,thus for starches entrapped in,cell wall like a barrier limit the digestive process,and stabilize the postprandial blood glucose.In this thesis,we choose 4 pulses from different genus,isolated intact pulse cells establish the model of whole pulse food.Morphology,crystalline structure,digestibility and other physicochemical properties are studied.Then the pinto bean cells which have the lowest digestive extent are prepared with heat-moisture treatment(HMT),and the effects of HMT on pinto bean cells are analyzed.The results revealed that the pulses cell wall can limit digestive process of starches entrapped in,and the difference among pulse cell wall contribute to dissimilar digestive curves.The cell walls barrier effect decreased after HMT.This study can provide scientific guidance for process of whole pulses.Isolated intact cells of cooked pinto bean,garbanzo bean,black-eyed pea and green split pea,cooked pinto bean starches as control.After analyzing the morphology,crystalline structure and in vitro digestibility,it was found that the structure of starches in intact cells are more ordered than pure pinto bean starch,providing that the starches surrounded by cell wall and protein matrix are limited to absorption and gelatinization.The Pearson's correlation analysis suggested that there is no significant correlation between the kinetic parameters and structural features of entrapped starch granules as well as the size of the cell particles,which suggested that the starch digestibility of isolated pulses is controlled by the access of digestive enzyme limited by the rigid cell wall and/or pulse protein matrix.The pinto bean cells and starches with different water content were treated by HMT under the condition of 100 ? for 8h.After analyzing morphology,crystallinity,thermal properties and digestibility,it was found that the HMT can changed the structure and properties of pinto bean starch significantly,but less effect on starches in cells.Combined the results of digestibility and CLSM,it was concluded that the cell wall can limited the digestive enzyme access to starch granules,but the barrier function will weaken with the increase of water content,resulting in higher digestive extent and rate of uncooked and cooked starch in pinto bean cells.